According to researchers at Stanford University and five other medical centers in the US, tests that can detect multiple mutations, have been used more frequently than the usual genetic tests aimed at detecting the presence of mutations in the genes BRCA1 and BRCA2 in women with breast cancer.
Clinicians recognize that the multi-faceted analyzes can provide more useful information for patients. Multigene assays accurately identify genetic variants associated with the disease than standard tests for BRCA1 and BRCA2.
A document describing the study, published May 10 in JAMA Oncology. Multigene assays allow to obtain information about the patient and his family members, who may be carriers of disease-related mutations. This allows for the genetic primary prevention of cancer in the patient's relatives.
The study involved more than 5,000 women who in the period from 2013 to 2015 had breast cancer diagnosed . A new feature of the study was that the results of genetic received directly from testing laboratories and have been associated with the data on the register of cancer. This relationship data provides greater accuracy of genetic information compared with previous studies.
Scientists have found that initially only about a quarter of the women were doing genetic analyzes. This number has remained relatively constant over the two-year period. However, the proportion of those who then did multigene assays increases over time, from 26% in early 2013 to 66% in mid-2015. In contrast, the proportion of women who have made tests for the BRCA only during the same period fell from 74 percent to 34 percent.
Multigene assays is approximately two times more frequently identified mutations associated with the disease than tests for BRCA. They accurately identify mutations of uncertain clinical significance, particularly racial or ethnic minorities. This finding emphasizes the need for research in the various population groups to clarify uncertainties and genetic analysis of racial differences in the results of genetic tests.
Time of delivery of analyzes was different. Although the majority of female subjects received the results before surgery to remove the tumor, many did not. About 33% of women who have passed multigene assays were examined after surgery, while approximately 20% of women do tests only for BRCA due to the recognition of clinicians that the interpretation of the multigene test results can be complex and require the expertise of Genetic Counselors, who are not always quickly available.
Since genetic testing has become more common and less expensive, it needs more genetic counselors. We need new models of assistance, which would prioritize patients for consultations.